1. Field of Invention
This invention generally relates to a drain trap with an alarm sensor, specifically to a drain tray of the type used in Heating, Ventilation and Air Conditioning system.
2. Prior Art
The Heating Ventilation Air Conditioning (HVAC) air handling units are provided with drain traps that provide a water seal-forming wall in condensate drain and prevent odor sanitary sewer gases, unfiltered air from entering the supply air and impacting indoor air quality. During the summer the air handling unit provides cooling, which in return develops condensation and is the primary element for a drain trap successful operation. The condensation is removed by the condensate drain which include a drain trap. During the winter months, when the air conditioning system is operating in the heating mode, condensate drain traps frequently become dry and do not provide a seal against the ingestion of polluted air or gases from sanitary sewers or other disposal places. Modem HVAC systems do not provide for detecting this critical malfunction. Current HVAC drain trap have no ability to detect if a drain trap is dry allowing the ingestion of polluted air from the sewer into the air conditioning system.
There are a number of patents which have been directed to HVAC related drain traps. None solve this serious problem. U.S. Pat. No. 6,584,995 discloses a device which allows a user to treat microbial and bacteria growth inside a HVAC condensate drain line or clear a clogged line without cutting into a drain line. Our valve is an in-line condensate drain line valve that can be installed easily, quickly and economically either during new construction or onto existing HVAC systems. The HVAC user can add household bleach to the condensate line, which inhibits microbial and bacteria growth without cutting into or disassembling the drain line. The design of our valve allows the user to perform safe routine maintenance to the HVAC drainage system without having to resort to expensive and repetitive service call repairs over the lifetime of the HVAC system. The valve is further designed to prevent undesirable reverse airflows into the HVAC system and home or building caused by a dry water trap in the condensate drain. The prevention of reverse airflows and reduction of microbial and bacteria growth will have a positive impact of indoor air quality. The U.S. Pat. No. 6,584,995 The HVAC Enviro-clean Valve as shown in FIG. 1, FIG. 2 offsets a malfunctioning drain trap with a check-valve located in the condensate drain line. The Drain Trap Alarm monitors drain trap operation 24 hours a day 7 days a week and alerts HVAC operating personnel if critical device is malfunctioning and execute commands to correct malfunction and sends data reporting when system is return to normal.
U.S. Pat. No. 4,497,337 discloses a device which automatically charges water into a sewer line from a water line containing water under variable pressure comprises a case having a longitudinal bore and means for connecting the case in series flow in the water line. A hollow shaft is mounted in the case and extends from the downstream portion a predetermined distance toward the upstream portion thereof. A piston slidably mounted on the shaft divides the bore of the case into an air chamber downstream of the piston and a water chamber upstream. A floating seal is mounted within the water chamber upstream of the piston and hollow shaft. The seal is advanced and retracted with fluctuations if water pressure in the water line. In its retracted position it charges the water chamber with water and compresses the air in the chamber. In its advanced position, it discharges the water content of the water chamber into the trap, thereby maintaining the water level thereof. The U.S. Pat. No. 4,497,337 provide continuous charging of water as shown in FIG. 3, FIG. 4, when fluctuations in pressures are sensed by floor primer valve. The Drain Trap Alarm provides continuous monitoring of condensate drain trap operation, malfunctions are immediately reported to HVAC operating personnel. Monitoring a condensate drain system is critical in preventing sanitary sewer gases from entering air conditioning system Condensate drain malfunctions result in occupants ingesting polluted air from HVAC system average malfunction last 3 to 6 months.
U.S. Pat. No. 4,918,935 discloses and apparatus to remove liquid from a chamber (B) of sub-atmospheric pressure in an air conditioning system wherein a liquid removal conduit (28) is connected to communicate with a chamber of sub-atmospheric pressure and with a condensate disposal place. Air at a pressure above ambient pressure, is delivered through an air line (30) into the flow control (10) between the chamber of sub-atmospheric pressure and the condensate disposal place. The flow rate of air into the liquid removal conduit (10) is controlled to permit flow of liquid through the conduit toward the condensate disposal place while preventing flow of gas through the conduit toward the chamber (A) of sub-atmospheric pressure. The flow rate of gas is controlled by a valve (48) in an air line (30) connected to the conduit (28) and by forming a tortuous path 50(a), 50(b), 50(c), and 50(d) in the flow control (10) to induce a loss in gas pressure without restricting flow of liquid.
U.S. Pat. No. 4,918,935 discloses a fluidic flow device that is supplied with air from the discharge of the HVAC fan This air is then directed to the condensate conduit which in return seals the sanitary sewer gases from entering the fan. When the fan is shut off during unoccupied mode the fluidic flow control seal vanishes allowing the sanitary gases to freely enter the fan chamber. Negative air pressure in a fan plenum when that fan is off is quite common i.e. building HVAC fans are off but toilet exhaust fans are all on and drawing air from all convenient sources. The fifth embodiment FIG. 11 illustrates the fluidic flow control including a U-trap piping design. The fluidic flow control seal vanishes when fan is off and the U-trap design provide a positive seal from sewer gases when condensate is available, condensate not available in winter. The Drain Trap Alarm provide continuous monitoring of drain trap operation, immediately notifying operating personnel of a drain trap malfunction. A automatic prime valve is activated during alarm establishing A seal and preventing ingestion of polluted air from the sanitary sewer into the air conditioning system.